No reason to fear the HPV vaccine
Nearly half of all teenage girls in the U.S. aren’t vaccinated against the sexually transmitted human papillomavirus—partly because their parents worry that getting the vaccine will encourage them to become sexually active. But a new study shows that those fears are misplaced. Girls who receive the shots, which protect against cervical, throat, and anal cancer later in life, are no more likely to have sex at an early age than those who don’t. Researchers followed 500 girls for three years after they got their first of three HPV shots, at age 11 or 12, and found that they were no more prone to contracting a sexually transmitted disease, becoming pregnant, or requesting contraceptives than were girls who skipped the shot. That result “really demonstrates that getting the HPV vaccination is not somehow a signal to start having unprotected sex,’’ Indiana University School of Medicine professor Gregory Zimet tells USA Today. Because the vaccine works best on those who have never had a sexual partner, experts say girls and boys—for whom the vaccine has proved less controversial—should receive their first doses as preteens. Nearly one in three American teenagers currently tests positive for HPV.
Born to poverty—or success
Climbing from poverty to success is no easier in the U.S. than it is in China, England, or many other countries. It’s also no easier today than it was 200 years ago. Those are the surprising conclusions of researchers who used international historical records to track the wealth, education, and life expectancy of people with the same family names from 1800 to the present. In this study of “social mobility,’’ researchers expected the average family’s fortunes to have shifted dramatically in 200 years, but they found the opposite. Whether you’re from Chile, China, England, Japan, Sweden, or the U.S., if people with your surname in 1800 were members of the elite, you’re likely to be elite, too; if your family name was linked to poverty back then, odds are it still is. “As much as 60 percent” of our social status “is determined at the time of conception,” economic historian Gregory Clark of the University of California, Davis, tells NPR.org. What’s really shocking about this finding, says Northwestern University economic historian Joseph Ferrie, is “that the number is as constant as it is.” In fact, when researchers looked even farther back in the record books, they found that the speed of social mobility hasn’t changed since the Middle Ages.
A new Earth nearby?
Astronomers have spotted an Earth-size planet in the solar system nearest to ours, igniting hope that more may be there as well—including potentially habitable ones. The discovery of rocky planets in the three-star Alpha Centauri system “is the story of the decade,” Yale University astronomer Debra Fischer tells The New York Times. Modern rockets would need 40,000 years to cover the 4.4 light-years that separate Earth from Alpha Centauri, but in galactic terms, the planet “is close enough you can almost spit there,” says astronomer Geoffrey Marcy of the University of California, Berkeley. Yet identifying the planet required extremely intensive observations. Researchers spent four years at the Geneva Observatory in Switzerland looking for a slight wobble, caused by the gravitational pull of an orbiting body, in the movements of Alpha Centauri B. The planet they discovered orbits so close to its sun that surface temperatures there likely surpass 2,000 degrees. But further observations could reveal additional Earth-size planets orbiting at distances that would make them hospitable to liquid water—and possibly to life. “Everything we know about this system so far,” says University of California, Santa Cruz, astronomer Greg Laughlin, “is extremely tantalizing.”
The perils of indoor air
Every breath you draw in a crowded office, classroom, or other indoor space could be making you dumber, ScienceNews.org reports. Researchers from the Lawrence Berkeley National Laboratory tested the reasoning skills of volunteers while exposing them to different levels of carbon dioxide. They found that as CO2 levels increased, the volunteers’ strategic and leadership abilities worsened to a degree “so astonishing that it was almost hard to believe,” says epidemiologist Mark Mendell. The highest levels of CO2 that researchers measured, 2,500 parts per million, could easily be found in buildings—including schools—that are “fully compliant with current standards” for ventilation, says Roger Hedrick of Architectural Energy Corp. Surprisingly, Hedrick says, even 1,000 ppm of carbon dioxide—a level that “used to be considered a benchmark of good ventilation,” though far above outdoor concentrations of less than 400 ppm—caused a significant dip in performance among study participants. Researchers have long thought that moderately elevated CO2 levels had no effect on people’s health or performance, Mendell says, which is “why these findings are so startling.’’ They suggest that efforts to make buildings more energy-efficient shouldn’t lock in the biggest source of indoor CO2—human exhalation.